Mr. Mookie is the yellow bunny squeaky toy belonging to Artie Springer on Dog City. Artie is seldom without Mr. Mookie, with whom he often converses. Mr. Mookie assumes an importance akin to Ernie's Rubber Duckie or Radar, Big Bird's teddy bear.
Mr. Mookie is normally seen as a prop toy, but first appears in animated form chasing Ace Hart and Eliot Shag in the first season episode "In Your Dreams." In the third season, the character was renamed "Mr. Moogie" and starred in several animated supporting segments of his own.